Bulk 5 Dehydration Experiment

• To find the nature of oscillations in the derivative of the lysimeter weight, we’ll show transpiration rate (S-G Smoothed 12 ) of all days relative to bowl of water (located on the same table)

• According to the proposed nature, during dehydration period, the amplitude (or number) of the oscillations should increase, relative to excess irrigation period.

Weights Data. Note two dehydration periods 3 and 6 days long each

Normal irrigation

Normal irrigation

Normal irrigation

Normal irrigation

Normal irrigation

Dehydration Day 1

Dehydration Day 2

Normal irrigation

Dehydration Day 1

Dehydration Day 2

Dehydration Day 3

Dehydration Day 4

Evaporation rates are fairly similar between the plant and the bowl. So is the amplitude ofthe oscillations.

Dehydration Day 5

Last dehydration day. The bowl evaporates more then the plant. The oscillations in the bowlevaporation rate have bigger amplitude, but follow the same pattern.

Rehabilitation Day 1. Normal irrigation

Notes to Discussion

• Similarity of the transpiration pattern between the plant and the bowl of water, in all days.

• Transpiration pattern during dehydration periods doesn’t look different from regular days.

• During the last dehydration days (March12) , the bowl of water evaporates more then the plant. So are the oscillations in it’s evaporation rate – with amplitude bigger then the plant that day.

Proposed conclusions

• Similarity of the pattern between the evaporation of the bowl of water and plant transpiration suggests that changing irradiation and temperature in the greenhouse causes changes in evaporation and transpiration rates during the day(as seen in the 1st derivative of the weight data).